I believe we should be able to search for threads that have zero replies so that people who don't get any replies on their threads don't feel left out. I've been browsing this forum for a while now and I've been observing that some threads are months old and yet they have no replies. It would be really cool if we could easily get to those threads. Therefore I request the administrators of this forum to perhaps add a "Maximum number of replies" field or something that allows users to lookup threads that have no replies.
The reason that some threads have zero replies is that they are essentially garbage threads with no or little value. So your garbage option/feature is without merit.
It's a new feature coming in XenForo 2 already. Probably will just wait for that. https://xf2demo.xenforo.com/threads/xenforo-2-0-0-developer-preview-8-released.2666/